Implantable stimulation devices deliver electrical stimuli to nerves and tissues for the therapy of various biological disorders, such as pacemakers to treat cardiac arrhythmia, defibrillators to treat cardiac fibrillation, cochlear stimulators to treat deafness, retinal stimulators to treat blindness, muscle stimulators to produce coordinated limb movement, spinal cord stimulators (SCS) to treat chronic pain, cortical and deep brain stimulators (DBS) to treat motor and psychological disorders, and other neural stimulators to treat urinary incontinence, sleep apnea, shoulder subluxation, etc. The description that follows will generally focus on the use of the invention within an SCS system, such as that disclosed in U.S. Pat. No. 6,516,227. However, the present invention may find applicability with any implantable medical device (IMD) or in any implantable medical device system.
As shown in FIG. 1, an SCS system typically includes an Implantable Pulse Generator (IPG) 10, which includes a biocompatible device case 12 formed of titanium, for example. The case 12 typically holds the circuitry and battery 14 necessary for the IPG to function. The IPG 10 is coupled to electrodes 16 via one or more electrode leads 18 (two of which are shown). The electrodes 16 are coupled to the IPG 10 at one or more lead connectors 20 fixed in a header 22, which can comprise an epoxy for example. In the illustrated embodiment, there are sixteen electrodes, although the number of leads and electrodes is application specific and therefore can vary. In an SCS application, two electrode leads 18 are typically implanted on the right and left side of the dura within the patient's spinal cord. The proximal ends of the leads 18 are then tunneled through the patient's tissue 60 (FIG. 2B) to a distant location, such as the buttocks, where the IPG case 12 is implanted, at which point the proximal ends are coupled to the lead connector(s) 20.
FIG. 2A shows a front view of an external controller 40 for communicating with the IPG 10, and FIG. 2B shows the external controller 40 and IPG 10 in cross section. Two coils (antennas) are generally present in the IPG 10: a telemetry coil 30 used to transmit/receive data via a bi-directional wireless communications link 55 to/from the external controller 40; and a charging coil 32 for recharging the IPG's rechargeable battery 14 using an external charger (not shown), which may also be incorporated with the external controller 40. Battery 14 may also be a non-rechargeable primary battery 14, in which case charging coil 32 would not be necessary. The coils 30 and 32 and other components necessary for IPG operation are electrically coupled to a circuit board 34. For example, an accelerometer 36 may be included within the IPG 10 to monitor patient movement or other forces. The telemetry coil 30 can be mounted within the header 22 of the IPG 10, or can be located within the case 12 as shown. The telemetry coil 30 can be coupled to telemetry circuitry 38 to modulate and demodulate a serial string of data bits sent to or received from the external controller 40. IPG 10 would also include main control circuitry, such as a microcontroller 230 (described later with reference to FIG. 7B).
The external controller 40, such as a hand-held programmer or a clinician's programmer, is used to send or adjust the stimulation parameters the IPG 10 will provide to the patient (such as which electrodes 16 are active, whether such electrodes sink and source current, and the pulse width, frequency, and intensity of pulses formed at the electrodes, etc.). The external controller 40 can also act as a receiver of data from the IPG 10, such as various data reporting on the IPG's status and the level of the IPG 10's battery 14. The external controller 40 is itself powered by a battery 42, but could also be powered by plugging it into a wall outlet for example. A Graphical User Interface (GUI) similar to that used for a cell phone is provided to operate the external controller 40, including buttons 44 and a display 46. The external controller 40 also includes a data telemetry coil 48. These and other components 45 necessary for IPG operation are electrically coupled in the external controller 40 to a circuit board 47.
Wireless data transfer between the IPG 10 and the external controller 40 typically takes place via magnetic inductive coupling between coils 30 and 48, each of which can act as the transmitter or the receiver to enable two-way communication between the two devices. A Frequency Shift Keying (FSK) protocol can be used to send data between the two coils 30 and 48 via link 55. Although use of an FSK protocol along link 55 is discussed below, use of this protocol is not universal, and other protocols employing different forms of modulation can be used to communicate between an external controller and an IPG, as one skilled in the art understands. Telemetry of data can occur transcutaneously though a patient's tissue 60.
Historically, external medical devices such as external controller 40 have been built by the manufacturer of the IPGs, and thus such external devices are generally dedicated to only communicate with such IPGs. The inventor has realized that there are many commercial mobile devices, such as multi-function mobile cell phones and tablets, that have the necessary configurable hardware and software to communicate using short-range protocols and thus may function as an external controller for an IPG or other implantable medical device. Using such mobile devices as external controllers for an implantable medical device would benefit both manufacturers and end users: manufacturers would not need to build dedicated external controllers that end users must buy, and end users could control their IPGs without the inconvenience of having to carry additional custom external controllers.
A Medical Device Application (MDA) for use on a mobile device, or other suitably-powerful external device capable of communicating with an IPG or other implantable medical device, is disclosed with improved functionality, which leverages the increased processing power and memory of such mobile devices to improve patient communications with his implant; to improve patient control of his implant; and to provide a patient more-detailed information concerning operation of his implant.